1. Field of the Invention
This invention relates to a method of controlling the position of an optical pickup head in an optical disc drive apparatus such as a CD (compact disc) drive apparatus, an MD (mini disc) drive apparatus, or a DVD (digital versatile disc) drive apparatus. This invention also relates to an apparatus for controlling the position of an optical pickup head in an optical disc drive apparatus. This invention further relates to an apparatus for detecting the position of an optical pickup head in an optical disc drive apparatus.
2. Description of the Related Art
A prior-art CD (compact disc) player includes an optical pickup head. When a CD is placed in the player, the optical pickup head starts to read out information from the CD. The prior-art CD player also includes a microcomputer and a traverse motor. The traverse motor serves to move the optical pickup head along a traverse direction between an inner most position and an outermost position with respect to the CD. The microcomputer is programmed to control the traverse motor.
The prior-art CD player further includes an innermost position switch connected to the microcomputer. When the optical pickup head reaches its innermost position, the body of the head encounters a control arm of the innermost position switch and changes the switch to its ON state. In this case, the microcomputer is informed that the innermost position switch changes to its ON state. The change of the innermost position switch to its ON state indicates that the optical pickup head reaches its innermost position. The microcomputer reverses the traverse motor in response to the change of the innermost position switch to its ON state. Accordingly, when the optical pickup head reaches its innermost position, the traverse motor is reversed so that the optical pickup head stops and then starts to move back toward its outermost position.
In the prior-art CD player, the connection between the innermost position switch and the microcomputer includes a pair of wiring lines, and a 2-pin connector. A simpler connection between the innermost position switch and the microcomputer has been desired.